ArcGIS Online uploaded feature class is empty

[deleted-user-m6DuRVNpNiGp]

I have a geodatabase feature class that I'm trying to uploaded to ArcGIS Online, either directly through ArcMap or by uploading the geodatabase. In each case the feature class uploads successfully; however, in each case the feature class is empty.

I have another feature class which is very similar that is uploading successfully. Here's the stats for both:

Number of records: 47 (successful FC), 48 (unsuccessful FC)
Projection: WGS_1984_Web_Mercator_Auxiliary_Sphere
Contents: Simple polylines, no Z values, no measures
Field names: Successful FC (OBJECTID, Shape, map, name, type, am, mid, pm, eve, Legend_name, Shape_Length)
            Unsuccessful FC (OBJECTID, Shape, LineAbbr,Legend_name,ROUTE_NAME,Shape_Length)
  -- map, name, Legend_name, LineAbbr, ROUTE_NAME are all strings; most of the rest are short integers except for the geometry ones

I've uploaded dozens of feature classes to ArcGIS Online and never had a problem. I have no idea what's going on here. This is a simple and straightforward feature class which displays just fine in ArcMap (10.2.1). Any thoughts? Thanks.

- geoff

[deleted-user-m6DuRVNpNiGp · Accepted solution]

I spoke with Esri technical support and they had me run the "Repair geometry" tool, which noted problems in the feature class' geometry, and then "repair geometry" to fix it. After that it uploaded successfully.